Conventionally, a liquid crystal display panel illuminated by a lighting device is used for displaying images in a vehicle. The liquid crystal display of the conventional apparatus has a control function for controlling a gradation value of pixel in the liquid crystal display panel, or for controlling light emission brightness of the lighting device as disclosed, for example, in Japanese patent documents JP-A-2004-284508, JP-A-2006-258783 or the like. The liquid crystal display panel in the conventional apparatus decreases the gradation value of the pixel or the light emission brightness of the lighting device for suppressing brightness of the image displayed on the display panel for the ease of viewing the image during the night or the like when external light brightness is low.
When the above control, that is, the decrease of the gradation value of the pixel or the light emission brightness of the lighting device is performed, the brightness of the image of the liquid crystal display is suppressed as a whole. In this case, the ease of viewing of meter images (images of instruments) for displaying vehicle condition values is improved by suppressing the brightness. However, an outside image that is generated by capturing outside world for calling attention for the situation outside of the vehicle as well as a warning image that warns abnormality of the vehicle or the images having similar purposes, that is, the images that require certain brightness, are not likely to achieve their original purposes.